The authors examined the diagnosis before the onset of schizophrenia and retrospectively evaluated the presence/absence of early prodromal symptoms (EPS) and their types (such as depressive symptoms, anxiety symptoms, and obsessive-compulsive [OC] symptoms) and the period from the onset of these symptoms to that of schizophrenia in 219 inpatients with schizophrenia diagnosed according to the DSM-IV(-TR). A diagnosis was made before the onset of schizophrenia in 53 patients (24.2%). The diagnoses were mood disorder in 39 patients, anxiety disorder in seven, obsessive-compulsive disorder (OCD) in three, adjustment disorder in two, and eating disorder in two. EPS were present in 65 (29.7%) of all patients, slightly more frequent in female patients (male:female = 1:1.41). In the group with EPS, depressive symptoms (61.5%) were most frequently observed, followed by anxiety symptoms (23.1%) and OC symptoms (9.2%). The age at onset for each type of symptom was significantly lower for OC symptoms (14.5 +/- 2.4 years) than for the other symptoms (approx. 20 years). The mean period from the onset of each symptom to that of schizophrenia was the shortest for depressive symptoms (2.7 +/- 3.1 years) and the longest (>4 years) for OC symptoms. These results as well as previous studies in Western countries showed that more non-specific and general symptoms are frequently present for some years before the onset of schizophrenia. With consideration of this point, efforts toward early detection of schizophrenia are important.